1,2,3-Thiadiazole derivatives or salts thereof and agrohorticultural disease controller and method for using the same

ABSTRACT

A 1,2,3-thiadiazole derivative represented by general formula (I) or a salt thereof:                    
     wherein R 1  is H, (halo) C 1 -C 4  alkyl, 5- or 6-membered heterocycle containing 1 to 3 same or different O, N or S, A is a group of the following formulas:                    
     wherein R 2  and R 3  are H, halogen, cyano, formyl, alkylthio, alkoxycarbonyl, substituted or unsubstituted phenyl, B is cyano or an unsubstituted or substituted 5- or 6-membered heterocycle containing 1-3 hetero atoms selected from O, N and S, and m is 0-4; an agrohorticultural disease controller containing said derivative.

This is a Continuation of International Application No. PCT/JP97/03467 filed Sep. 29, 1997 which designated the U.S.

TECHNICAL FIELD

The present invention relates to 1,2,3-thiadiazole derivatives and salts thereof, and agrohorticultural disease controller containing said compound as an active ingredient, and method for using the disease controller.

BACKGROUND ART

1,2,3-Thiadiazoles are disclosed in JP-A-2-149579/1990 as an agent for treating central nervous system diseases, in JP-A-54-9272/1979, JP-A-3-181463/1991, JA-A-4-234881/1992, Canadian Patent 947297, etc. as a herbicide or a plant growth regulator, and in WO 9501340 and JP-A-7-252242/1995 as a fungicide.

DISCLOSURE OF THE INVENTION

With the aim of creating a novel agrohorticultural disease controller, the present inventors have conducted extensive studies to find that the 1,2,3-thiadiazole derivatives of the present invention represented by general formula (I) or salts thereof which are novel compounds not found in literature are useful as an agrohorticultural disease controller. Based on this finding, the present invention has been accomplished.

The present invention relates to 1,2,3-thiadiazole derivatives represented by the following general formula (I) or salts thereof, an agrohorticultural disease controller containing said compounds as an active ingredient, and a method for using said disease controller:

wherein R¹ represents hydrogen atom, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₁ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, 5- or 6-membered heterocycle containing 1 to 3 same or different heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups;

A represents a group of the following formula:

(wherein R² and R³, same or different, represent hydrogen atom, halogen atom, cyano group, formyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, C₁-C₄ alkylsulfinyl group, C₁-C₄ alkylsulfonyl group, C₁-C₄ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, C₁-C₄ alkyl group and C₁-C₄ alkoxycarbonyl group; further, R² and R³ may be taken conjointly to form a 3- to 7-membered ring including a C₂-C₆ alkylene group which may be intercepted by

—O—,

—S (O)_(n)-in which n is an integer of 0 to 2,

—CO— or

—NR⁸— in which R⁸ represents hydrogen atom, formyl group, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, C₂-C₄ alkenyl group, halo C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, halo C₂-C₄ alkynyl group, C₁-C₄ alkylthio group, C₁-C₄ alkylsulfinyl group, C₁-C₄ alkylsulfonyl group, C₁-C₄ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group and phenyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group; and said 3- to 7-membered ring may be substituted by one or more same or different substituents selected from the group consisting of halogen atom and C₁-C₄ alkyl group; and m represents an integer of 0 to 4), or

in which R² and R³ are as defined above, or

in which R² and R³ are as defined above, or

in which R² and R³ are as defined above; and

in the case that m is 0 in the definition of A, B represents cyano group, 5- or 6-membered heterocycle having 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different C₁-C₄ alkyl or phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 C₁-C₄ alkyl or phenyl groups, carbamoyl C₁-C₄ alkyl group and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different C₁-C₄ alkyl or phenyl groups, or

—C(═X)R⁴

(in which R⁴ represents hydrogen atom, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, C₂-C₄ alkenyl group, halo C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, halo C₂-C₄ alkynyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group and phenyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group and phenyl group, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group and phenyl group, and

X represents O, S,

N—R⁶ in which R⁶ is as defined later,

NO—R⁶ in which R⁶ is as defined later,

N(→O)—R⁶ in which R⁶ is as defined later,

NN(R⁶)R⁷ in which R⁶ and R⁷ are as defined later, or

NN═C(R⁶)R⁷ (in which R⁶ and R⁷, same or different, represent hydrogen atom, halogen atom, formyl group, C₁-C₄ alkyl group, C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, C₁-C₄ alkylsulfonyl group, halo C₁-C₄ alkylsulfonyl group, C₁-C₂₀ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group, amino group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group, amino group and C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, substituted phenylcarbonyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group, phenyl group and substituted phenyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group and halo C₁-C₄ alkoxy group, phenylsulfonyl group, substituted phenylsulfonyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, thiocarbamoyl group, substituted thiocarbamoyl group substituted by same or different C₁-C₄ alkyl or phenyl group, C₁-C₄ alkoxy carbonimidoyl group, substituted C₁-C₄ alkoxy carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylthio carbonimidoyl group, substituted C₁-C₄ alkylthio carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylsulfinyl carbonimidoyl group, substituted C₁-C₄ alkylsulfinyl carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylsulfonyl carbonimidoyl group, substituted C₁-C₄ alkysulfonyl carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, amidino group, substituted amidino group having same or different substituents selected from the group consisting of C₁-C₆ alkyl and phenyl groups, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups; and R⁶ and R⁷ may be taken conjointly to form a 3- to 7-membered ring including a C₂-C₆ alkylene group which may be intercepted by

—O—,

—S(O)_(n)— in which n is as defined above,

—CO—, or

—NR⁸— in which R⁸ is as defined above, and said 3- to 7-membered ring may have same or different substituents selected from the group consisting of halogen atom and C₁-C₄ alkyl group)); and

in cases where m is 1 or greater, B represents hydrogen atom, halogen atom, cyano group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 3 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups,

—C(═X)R⁵

(in which X is as defined above; and R⁵ represents hydrogen atom, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, C₂-C₄ alkenyl group, halo C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, halo C₂-C₄ alkynyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, 5- to 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups,

O—R⁶ in which R⁶ is as defined above,

S(O)_(n)—R⁶ in which n and R⁶ are as defined above, or

N(R⁶)R⁷ in which R⁶ and R⁷ are as defined above),

(wherein R⁵ is as defined above; and R⁹ and R¹⁰, same or different, represent formyl group, C₁-C₄ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group; further, R⁹ and R¹⁰ may be taken conjointly to form a 3- to 7-membered ring including a C₂ to C₆ alkylene group which may be intercepted by

—O—,

—S(O)_(n)— in which n is as defined above,

—CO—, or

—N(R⁸)— in which R⁸ is as defined above, and said 3- to 7-membered ring may have one or more same or different substituents selected from the group consisting of halogen atom and C₁-C₄ alkyl group),

O—R⁶ in which R⁶ is as defined above,

S(O)_(n)—R⁶ in which R⁶ and n are as defined above,

N(R⁶)R⁷ in which R⁶ and R⁷ are as defined above,

N═C(R⁶)R⁷ in which R⁶ and R⁷ are as defined above, or

ON═C(R⁶)R⁷ in which R⁶ and R⁷ are as defined above.

BEST MODE FOR CARRYING OUT THE INVENTION

In the definitions of the substituents in the 1,2,3-thiadiazole derivatives of the present invention represented by general formula (I), the term “halogen atom” means chlorine atom, bromine atom, iodine atom or fluorine atom; the term “C₁-C₈ alkyl group” means a straight or branched chain alkyl group having 1 to 8 carbon atoms such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl and the like; the term “halo C₁-C₄ alkyl group” means a straight or branched chain alkyl group having 1 to 4 carbon atoms and substituted by one or more same or different halogen atoms, the term “C₂-C₄ alkenyl group” means a straight or branched chain alkenyl group having 2 to 4 carbon atoms and a double bond, and the term “halo C₂-C₄ alkenyl group” means a straight or branched chain alkenyl group having 2 to 4 carbon atoms and substituted by at least one same or different halogen atom.

The term “C₂-C₄ alkynyl group” means a straight or branched chain alkynyl group having 2 to 4 carbon atoms and a triple bond, the term “halo C₂-C₄ alkynyl group” means a straight or branched chain alkynyl group having 2 to 4 carbon atoms and substituted by one or more same or different halogen atoms, and the term “5- or 6-membered heterocycle containing at least one same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom” means a 5- or 6-membered ring such as furan, thiophene, pyrrole, oxazole, thiazole, isothiazole, pyrazole, imidazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,2,4-triazole, pyridine, pyridazine, pyrimidine, pyrazine, pyrrolidine, piperidine, morpholine, thiomorpholine, dithiolane, dithiane, piperazine, dioxolane, imidazolidine and the like.

As examples of the salt of 1,2,3-thiadiazole derivative represented by general formula (I), there can be referred to salts of alkali metals such as sodium, potassium and the like, salts of alkaline earth metals such as calcium, magnesium and the like, ammonium salts, substituted ammonium salts substituted by one or more same or different substituents selected from the group consisting of C₁-C₁₂ alkyl group, phenyl group, substituted phenyl group, benzyl group or substituted benzyl group, guanidium salt and the like.

As preferred substituents of the present invention, the following are referred to. Thus, as R¹, methyl, ethyl, n-propyl, cyclopropyl and the like are preferred. As A, a single bond (B is directly linked to thiadiazole ring) or methylene are preferred. In a case where A is a single bond, B is preferably cyano, formyl, hydroxyiminomethyl, benzyloxyiminomethyl, hydrazonomethyl, phenylhydrazonomethyl, imidazolin-2-yl, 4-methylthiazol-2-yl and the like. In a case where A is methylene, B is preferably chlorine atom, hydroxyl group, methoxy group, benzyloxy group, acetoxy group, benzoyloxy group, ethoxycarbonyloxy group, amino group and hydrochloride thereof, diethylamino group, dipropenylamino group, benzoylamino group, p-toluenesulfonylamino group, 3-phenylureido group, 4-methl-1,2,3-thiadiazol-5-ylmethoxy group and the like.

The 1,2,3-thiadiazole derivatives of the present invention represented by general formula (I) and salts thereof can be produced, for example, by the Production processes exemplified below.

Production process 1

wherein R¹ is as defined above and R¹¹ represents C₁-C₈ alkyl group.

A 1,2,3-thiadiazole derivative represented by general formula (I-1) can be produced by reducing a compound of general formula (II) in the presence of a reductant to form a 1,2,3-thiadiazole derivative represented by general formula (I-1) and, after isolating or without isolating the thus formed (I-1), oxidizing (I-1) in the presence of an oxidant.

This reaction can be performed according to the description of Shin Jikken Kagaku Koza, Vol. 15 (II), p. 191 (Maruzen K. K.); Jikken Kagaku Koza (4th edition), Vol. 23(V), p. 43 (Maruzen K. K.), etc.

Production process 2

wherein R¹ and R¹¹ are as defined above, and R^(4′) represents phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting C₁-C₄ alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups.

A 1,2,3-thiadiazole derivative represented by general formula (I-3) can be produced by hydrolyzing a compound of general formula (II) and then reacting it with thionyl chloride to form a compound represented by general formula (III), and after isolating compound (III) or without isolating (III), reacting (III) with a compound of general formula (IV) in the presence of a catalyst.

This reaction can be performed according to the description of “Shin Jikken Kagaku Koza”, Vol. 14(II), p. 794.

Production process 3

wherein R¹, R⁴ and R⁶ are as defined above.

A 1,2,3-thiadiazole derivative represented by general formula (I-5) can be produced by reacting a 1,2,3-thiadiazole derivative of general formula (I-4) with a compound represented by general formula (V).

This reaction can be performed according to the description of “Jikken Kagaku Koza” (4th edition), Vol. 20 (V), p. 353.

Production process 4

wherein R¹, R⁴, R⁶ and R⁷ are as defined above.

A 1,2,3-thiadiazole derivative represented by general formula (I-6) can be produced by reacting a 1,2,3-thiadiazole derivative of general formula (I-4) with a compound represented by general formula (VI).

This reaction can be performed according to the description of Org. Synth. Coll. VI, p.12 (1988).

Production process 5

wherein R¹ and R⁶ are as defined above and Hal represents halogen atom.

A 1,2,3-thiadiazole derivative represented by general formula (I-8) or (I-9) can be produced by treating a 1,2,3-thiadiazole derivative represented by general formula (I-1) with a halogenating agent such as thionyl chloride or phosphorus tribromide to form a compound represented by general formula (III′), and after isolating the compound (III′) or without isolating (III′), reacting the compound (III′) with sodium formimide and then with an acid such as hydrochloric acid to form a salt of a 1,2,3-thiadiazole derivative represented by general formula (I-7), and then reacting the salt (I-7) with a compound of formula (VII). Further, if a salt of the 1,2,3-thiadiazole derivative of formula (I-7) is reacted with an isocyanate of formula (VIII), a 1,2,3-thiadiazole derivative of general formula (I-8′) can be obtained.

This reaction can be performed according to the description of “Jikken Kagaku Koza” (4th edition), Vol. 19 (I), p. 438; Synthesis, 615 (1990); “Jikken Kagaku Koza” (4th edition), Vol. 22 (II), p. 1142; “Shin Jikken Kagaku Koza”, Vol. 14 (III), p. 1631; etc.

Production process 6

wherein R¹, R⁶ and Hal are as defined above.

A 1,2,3-thiadiazole derivative represented by general formula (I-10) can be produced by reacting a 1,2,3-thiadiazole derivative of formula (I-1) with a compound represented by formula (VII) in the presence of a base.

This reaction can be performed according to the description of “Jikken Kagaku Koza” (4th edition), Vol. 22 (V), p..50.

Production process 7

wherein R¹, R⁶ and Hal are as defined above and n′ represents an integer of 1-2.

A 1,2,3-thiadiazole derivative represented by general formula (I-12) can be produced by reacting a 1,2,3-thiadiazole derivative of general formula (I-1) with a compound represented by general formula (IX) in the presence of a base to form a 1,2,3-thiadiazole derivative represented by general formula (I-11), and after isolating the compound (I-11) or without isolation it, oxidizing the derivative (I-11) in the presence of an oxidant.

This reaction can be performed according to the description of “Shin Jikken Kagaku Koza”, Vol. 14 (III), p. 1716; “Jikken Kagaku Koza” (4th edition), Vol. 24 (VI), p. 365; etc.

Production process 8

wherein R¹ and Hal are as defined above; and R¹² and R¹³, same or different, represent C₁-C₄ alkyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, carbamoyl group, substituted carbamoyl having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups.

A 1,2,3-thiadiazole derivative represented by general formula (I-13) can be produced by reacting a compound represented by general formula (X) with phosphorus pentasulfide and then with a compound represented by general formula (XI).

This reaction can be performed according to the description of “Shin Jikken Kagaku Koza”, Vol. 14 (IV), p. 2198; Org. Synth., Coll. Vol. III, p. 332 (1955); etc.

Production process 9

wherein R¹ is as defined above, R¹⁴ represents hydrogen atom or C₁-C₄ alkyl, and W represents C₃-C₆ alkylene group which may be substituted by C₁-C₄ alkyl group and may be intercepted by

—O—,

—NR⁶— in which R⁶ is as defined above,

—S (O)_(n)— in which n is as defined above, or

—CO—.

A 1,2,3-thiadiazole derivative represented by general formula (I-15) can be produced by subjecting a compound of general formula (X) to a dehydrating reaction to form a 1,2,3-thiadiazole derivative represented by general formula (I-14), and after isolating the derivative (I-14) or without isolating it, reacting the derivative (I-14) with a compound represented by general formula (XII).

This reaction can be performed according to the description of “Shin Jikken Kagaku Koza”, Vol. 14 (II), p. 1190.

Production process 10

wherein R¹, R², R³ and B are as defined above.

A 1,2,3-thiadiazole derivative represented by general formula (I-17) can be produced by reacting a 1,2,3-thiadiazole derivative represented by general formula (I-16) with a compound represented by formula (XIII) or formula (XIV).

This reaction can be performed according to the description of “Shin Jikken Kagaku Koza”, Vol. 14 (I), p. 224; JP-A-7-165757/1995; etc.

The compound of general formula (II) used as a starting compound for production of the 1,2,3-thiadiazine derivative represented by general formula (I) can be produced, for example, by the following method.

wherein R¹ is as defined above, R¹¹ represents C₁-C₈ alkyl group, and R¹² represents C₁-C₄ alkyl group, C₁-C₄ alkoxy group or amino group which may have a substituent.

A compound represented by general formula (II) can be produced by reacting a compound represented by general formula (XV) with a compound represented by general formula (XVI) to form a compound represented by general formula (XVII), and after isolating the compound (XVII) or without isolating it, subjecting the compound (XVII) to ring closure using thionyl chloride.

This reaction can be preformed according to the description of J. Am. Chem. Soc., 77, 5359 (1955), etc.

Next, typical examples of the 1,2,3-thiadiazole derivative of the present invention represented by general formula (I) are mentioned below. The invention is by no means limited by these examples.

In Table 1, meaning of the abbreviations are as follows.

Ph: phenyl group

cyclo: alicyclic hydrocarbon

TABLE 1 General formula (I) (I)

No R¹ A B Property  1 H — COPh m.p. 60-61° C.  2 H CH₂ Cl  3 H CH₂ OH  4 H CH₂ OCH₃  5 H CH₂ OCH₂Ph  7 CH₃ — CHO nD 1.5555(26° C.)  8 CH₃ — COCH₃  9 CH₃ — COPh nD 1.6145(22° C.)  10 CH₃ — CO(2-Cl-Ph)  11 CH₃ — CO(4-Cl-Ph)  12 CH₃ — CO(2-CH₃-Ph)  13 CH₃ — CO(4-CH₃-Ph)  14 CH₃ — CO(4-i-C₃H₇-Ph)  15 CH₃ — CO(4-CH₃O-Ph)  16 CH₃ — CO(4-t-C₄H₉-Ph)  17 CH₃ — CO-(1-CH₃—Q₂₎ m. p. 85-90° C.  18 CH₃ — CN m. p. 50.4° C.  19 CH₃ — CH═NOH m. p. 270° C.(dec.)  20 CH₃ — CH═NOCH₃ m. p. 97° C.  21 CH₃ — CH═NOCH₂Ph nD 1.5998(25° C.)  22 CH₃ — CH═NOCH₂(2-Cl-Ph)  23 CH₃ — CH═NOCH₂(3-Cl-Ph)  24 CH₃ — CH═NOCH₂(4-Cl-Ph) m. p. 70-80° C.  25 CH₃ — CH═NOCH₂(2-CH₃-Ph)  26 CH₃ — CH═NOCH₂(3-CH₃-Ph)  27 CH₃ — CH═NOCH₂(4-CF₃-Ph)  28 CH₃ — CH═NOCH₂(4-OH-Ph)  29 CH₃ — CH═NOCH₂(4-CH₃O-Ph)  30 CH₃ — CH═NOCH₂(4-CF₃O-Ph)  31 CH₃ — CH═NOCH₂(4-NH₂-Ph)  32 CH₃ — CH═NOCH₂(4-NO₂-Ph)  33 CH₃ — CH═NOCH₂(4-CN-Ph)  34 CH₃ — CH═NOCH₂(4-COOCH₃-Ph)  35 CH₃ — CH═NNH₂ m. p. 81° C.  36 CH₃ — CH═NNHCH₃  37 CH₃ — CH═NNHPh m. p. 218° C.  38 CH₃ — CH═NNH(2-Cl-Ph)  39 CH₃ — CH═NNH(2-F-4-Cl-Ph)  40 CH₃ — CH═NNH(3,5-Cl₂-Ph)  41 CH₃ — CH═NNH(3-Cl-Ph)  42 CH₃ — CH═NNH(3-i-C₃H₇C-Ph)  43 CH₃ — CH═NNH(4-CF₃-Ph)  44 CH₃ — CH═NNH(4-Cl-Ph)  45 CH₃ — CH═NNHCOOCH₃  46 CH₃ — CH═NNHCOOC₄Hg-t  47 CH₃ — CH═NNHCONHCH₃  48 CH₃ — CH═NNHCONHC₂H₅  49 CH₃ — CH═NNHCON(CH₃)Ph  50 CH₃ — CH═NNHCONH(4-Cl-Ph)  51 CH₃ — CH═NNHCONH(4-t-C₄H₉-Ph)  52 CH₃ — CH═NNHCONH(4-CF₃-Ph)  53 CH₃ — CH═NNHCONH(4-i-C₃H₇C-Ph)  54 CH₃ — CH═NNHCONH(4-CF₃C-Ph)  55 CH₃ — CH═NNHCSNHCH₃  56 CH₃ — CH═NNHC(N(CH₃)₂)═NCH₃  57 CH₃ — CH═NNHC(CCH₃)═NCH₃  58 CH₃ — CH═NNHC(SCH₃)═NCH₃  59 CH₃ — CH═NNHC(SCCH₃)═NCH₃  60 CH₃ — CH═NNH-(4,6-(CH₃)₂—Q₃) m. p. 182-183° C.  61 CH₃ — C(Ph)═NOH m. p. 172° C.  62 CH₃ — C(Ph)═NOCH₃ nD 1.5905(22.8°C.)  63 CH₃ — C(Ph)═NOC₈H₁₇  64 CH₃ — C(Ph)═NOCH₂CH═CH₂  65 CH₃ — C(Ph)═NOCH₂CCl═CH₂  66 CH₃ — C(Ph)═NOCH₂C ≡CH nD 1.5945(22.8° C.)  67 CH₃ — C(Ph)═NOCH₂C ≡CBr  68 CH₃ — C(Ph)═NOCH₂C ≡CCl  69 CH₃ — C(Ph)═NOCH₂Ph nD 1.6183(23.9° C.)  70 CH₃ — C(Ph)═NOCH₂(4-Cl-Ph)  71 CH₃ — C(Ph)═NOCH₂(3,4-Cl₂-Ph)  72 CH₃ — C(Ph)═NOCH₂(2,4,6-Cl₃-Ph)  73 CH₃ — C(Ph)═NOCH₂(2-CH₃-Ph)  74 CH₃ — C(Ph)═NOCH₂(3-CH₃-Ph)  75 CH₃ — C(Ph)═NOCH₂(4-CH₃-Ph)  76 CH₃ — C(Ph)═NOCH₂(3-CH₃O-Ph)  77 CH₃ —

m. p. 180.1° C.  78 CH₃ —

m. p. 116.3° C.  79 CH₃ — C(Ph)═NNH₂ m. p. 72.3° C.  80 CH₃ — C(Ph)═NNHCOCC₂H₅  81 CH₃ — C(Ph)═NNHCSNHPh  82 CH₃ — 3-CN—Q₂ m. p. 190-200° C.  83 CH₃ — Q₄  84 CH₃ — 5-CH₃-5-i-C₃H₇-4-(═O)—Q₄ m. p. 59° C.  85 CH₃ — 5-(CH₃)₂—Q₅ m. p. 114° C.  86 CH₃ — 4-(CH₃)₂-5-(═O)—Q₆ m. p. 107° C.  87 CH₃ — 4,6-(CH₃)₂—Q₃ m. p. >180° C.  88 CH₃ — 4-CH₃—Q₇ m. p. 89° C.  89 CH₃ — 4-t-C₄H₅—Q₇ m. p. 61° C.  90 CH₃ — 4-(2-Cl-Ph)-Q₇ m. p. 136° C.  91 CH₃ — 4-(4-Cl-Ph)-Q₇ m. p. 125° C.  92 CH₃ — 4-(2,4-C₁₂-Ph)-Q₇ m. p. 170° C.  93 CH₃ — 4-(4-CH₃-Ph)-Q₇ m. p. 118° C.  94 CH₃ — 5-CH₃-4-Ph-Q₇ m. p. 151° C.  95 CH₃ — 4-CONHCH₃—Q₇ m. p. 144° C.  96 CH₃ — 4-CH₂COOH—Q m. p. 196° C.  97 CH₃ — 4-CH₂CONH₂—Q₇ m. p. 182° .C  98 CH₃ — 4-CH₂COOC₂H₅—Q₇ m. p. 98° C.  99 CH₃ — 4-CH₂CONHCH₃—Q₇ m. p. 155° C. 100 CH₃ — 4-CH₂CON(C₂H₅)₂—Q₇ m. p. 132° C. 101 CH₃ — 5-Ph-Q₈ m. p. 154° C. 102 CH₃ — 5-SH—Q₈ m. p. 182° C. 103 CH₃ — 5-SCH₃—Q₈ m. p. 65° C. 104 CH₃ CH₂ Cl nD 1.5590(26° C.) 105 CH₃ CH₂ OH nD 1.553(21° C.) 106 CH₃ CH₂ OCH₃ nD 1.5180(26° C.) 107 CH₃ CH₂ OC₄H₉-n 108 CH₃ CH₂ OC₈H₁₇-n 109 CH₃ CH₂ OCH₂Ph nD 1.5730(25° C.) 110 CH₃ CH₂ OCH₂(2-Cl-Ph) 111 CH₃ CH₂ OCH₂(3-Cl-Ph) 112 CH₃ CH₂ OCH₂(4-Cl-Ph) 113 CH₃ CH₂ OCH₂(2-CH₃-Ph) 114 CH₃ CH₂ OCH₂(3-CH₃-Ph) 115 CH₃ CH₂ OCH₂(4-t-C₄H₉-Ph) 116 CH₃ CH₂ OCH₂(4-CF₃-Ph) 117 CH₃ CH₂ OCH₂(2,4-(CH₃)₂-Ph) 118 CH₃ CH₂ OCH₂(3,4-(CH₃)₂-Ph) 119 CH₃ CH₂ OCH₂(4-OH-Ph) 120 CH₃ CH₂ OCH₂(4-CH₃O-Ph) 121 CH₃ CH₂ OCH₂(4-CF₃O-Ph) 122 CH₃ CH₂ OCH₂(2,4-(CH₃O)₂-Ph) 123 CH₃ CH₂ OCH₂(3,4-(CH₃O)₂-Ph) 124 CH₃ CH₂ OCH₂(4-NH₂-Ph) 125 CH₃ CH₂ OCH₂(4-NO₂-Ph) 126 CH₃ CH₂ OCH₂(4-COCCH₃-Ph) 127 CH₃ CH₂ OCH₂(4-COOC₄H₉-t-Ph) 128 CH₃ CH₂ OCH₂(4-CN-Ph) 129 CH₃ CH₂ OCH₂(4-CH₃—Q₁) nD 1.547(26.3° C.) 130 CH₃ CH₂ OPh 131 CH₃ CH₂ O(2-Cl-Ph) 132 CH₃ CH₂ O(3-Cl-Ph) 133 CH₃ CH₂ O(4-Cl-Ph) 134 CH₃ CH₂ O(2-CH₃-Ph) 135 CH₃ CH₂ O(3-CH₃-Ph) 136 CH₃ CH₂ O(4-t-C₄H₉-Ph) 137 CH₃ CH₂ O(4-CF₃-Ph) 138 CH₃ CH₂ O(2,4-(CH₃)₂-Ph) 139 CH₃ CH₂ O(3,4-(CH₃)2-Ph) 140 CH₃ CH₂ O(4-OH-Ph) 141 CH₃ CH₂ O(4-CH₃O-Ph) 142 CH₃ CH₂ O(4-CF₃O-Ph) 143 CH₃ CH₂ O(2,4-(CH₃O)₂-Ph) 144 CH₃ CH₂ O(3,4-(CH₃O)₂-Ph) 145 CH₃ CH₂ O(4-NH₂-Ph) 146 CH₃ CH₂ O(4-NO₂-Ph) 147 CH₃ CH₂ O(4-COOCH₃-Ph) 148 CH₃ CH₂ O(4-COOC₄H₉-t-Ph) 149 CH₃ CH₂ O(4-CN-Ph) 150 CH₃ CH₂ O—COCH₃ nD 1.3580(25° C.) 151 CH₃ CH₂ O—COC₂H₅ 152 CH₃ CH₂ O—COC₃H₇-n 153 CH₃ CH₂ O—COC₃H₇-i 154 CH₃ CH₂ O—COC₄H₉-t 155 CH₃ CH₂ O—COC₄H₉-s 156 CH₃ CH₂ O—COCl₇H₃₅-n 157 CH₃ CH₂ O—COC₆H₁₁-cyclo 158 CH₃ CH₂ O—COCH═CH₂ 159 CH₃ CH₂ O—COCH═CHPh 160 CH₃ CH₂ O—COCH₂Cl 161 CH₃ CH₂ O—COCF₃ 162 CH₃ CH₂ O—COPh m. p. 50-53° C. 163 CH₃ CH₂ O—CO(2-Cl-Ph) 164 CH₃ CH₂ O—CO(3-Cl-Ph) 165 CH₃ CH₂ O—CO(4-Cl-Ph) 166 CH₃ CH₂ O—CO(2-CH₃-Ph) 167 CH₃ CH₂ O—CO(3-CH₃-Ph) 168 CH₃ CH₂ O—CO(4-t-C₄H₉-Ph) 169 CH₃ CH₂ O—CO(4-CF₃-Ph) 170 CH₃ CH₂ O—CO(2,4-(CH₃)₂-Ph) 171 CH₃ CH₂ O—CO(3,4-(CH₃)₂-Ph) 172 CH₃ CH₂ O—CO(4-CH₃O-Ph) 173 CH₃ CH₂ O—CO(4-CF₃O-Ph) 174 CH₃ CH₂ O—CO(2,4-(CH₃O)₂-Ph) 175 CH₃ CH₂ O—CO(3,4-(CH₃O)₂-Ph) 176 CH₃ CH₂ O—CO(4-NO₂-Ph) 177 CH₃ CH₂ O—CO(4-CCOCH₃-Ph) 178 CH₃ CH₂ O—CO(4-CCOC₄H₉-t-Ph) 179 CH₃ CH₂ O—CO(4-CN-Ph) 180 CH₃ CH₂ O—COOC₂H₅ nD 1.5041(26° C.) 181 CH₃ CH₂ O—COOC₄H₉-i 182 CH₃ CH₂ ON═C(CH₃)₂ 183 CH₃ CH₂ ON═C(CH₃)C₂H₅ 184 CH₃ CH₂ ON═C₆H₁₀-cyclo 185 CH₃ CH₂ ON═CHPh 186 CH₃ CH₂ ON═CH(2-Cl-Ph) 187 CH₃ CH₂ ON═CH(3-Cl-Ph) 188 CH₃ CH₂ ON═CH(4-Cl-Ph) 189 CH₃ CH₂ ON═CH(2-CH₃-Ph) 190 CH₃ CH₂ ON═CH(3-CH₃-Ph) 191 CH₃ CH₂ ON═CH(4-C₄H₉-t-Ph) 192 CH₃ CH₂ ON═CH(4-CF₃-Ph) 193 CH₃ CH₂ ON═CH(2,4-(CH₃)₂-Ph) 194 CH₃ CH₂ ON═CH(3,4-(CH₃)₂-Ph) 195 CH₃ CH₂ ON═CH(4-CH-Ph) 196 CH₃ CH₂ ON═CH(4-CH₃C-Ph) 197 CH₃ CH₂ ON═CH(4-CF₃C-Ph) 198 CH₃ CH₂ ON═CH(2,4-(CH₃C)₂-Ph) 199 CH₃ CH₂ ON═CH(3,4-(CH₃C)₂-Ph) 200 CH₃ CH₂ ON═CH(4-NH₂-Ph) 201 CH₃ CH₂ ON═CH(4-NC₂-Ph) 202 CH₃ CH₂ ON═CH(4-COOCH₃-Ph) 203 CH₃ CH₂ ON═C(CH₃)Ph 204 CH₃ CH₂ OSO₂CH₃ 205 CH₃ CH₂ OSO₂CF₃ 206 CH₃ CH₂ OSO₂Ph 207 CH₃ CH₂ OSO₂(4-Br-Ph) 208 CH₃ CH₂ OSO₂(4-CH₃-Ph) Paste 209 CH₃ CH₂ SPh nD 1.636(24.6° C.) 210 CH₃ CH₂ SOPh 211 CH₃ CH₂ SO₂Ph m. p. 118° C. 212 CH₃ CH₂ SO₂(4-CH₃-Ph) 213 CH₃ CH₂ SO₂(4-NO₂-Ph) 214 CH₃ CH₂ SCH₂Ph nD 1.612(24.6° C.) 215 CH₃ CH₂ SO₂CH₂Ph m. p. 116° C. 216 CH₃ CH₂ SCON(CH₂CH═CH₂)₂ 217 CH₃ CH₂ SCO—Q₉ 218 CH₃ CH₂ SCOOC₂H₅ 219 CH₃ CH₂ SCSN(C₂H₅)₂ 220 CH₃ CH₂ NH₂.HCl m. p. >250° C. 221 CH₃ CH₂ N(C₂H₅)₂ Paste 222 CH₃ CH₂ N(CH₂CH═CH₂)₂ Paste 223 CH₃ CH₂ NHPh 224 CH₃ CH₂ NH(4-CH₃-Ph) 225 CH₃ CH₂ NHCOCH₃ 226 CH₃ CH₂ NHCOC₂H₅ 227 CH₃ CH₂ NHCOC₃H_(7-n) 228 CH₃ CH₂ NHCOC₃H-i 229 CH₃ CH₂ NHCOC₄H₉-t m. p. 93-94° C. 230 CH₃ CH₂ NHCOC₄H₉-s 231 CH₃ CH₂ NHCOC₁₇H₃₅-n 232 CH₃ CH₂ NHCOC₃H₅-cyclo m. p. 75-78° C. 233 CH₃ CH₂ NHCO(2,2-Cl₂—C₃H₅-cyclo) 234 CH₃ CH₂ NHCOC₆H₁₁-cyclo 235 CH₃ CH₂ NHCOCH═CH₂ 236 CH₃ CH₂ NHCOCH═CHPh 237 CH₃ CH₂ NHCOCH₂Cl 238 CH₃ CH₂ NHCOCF₃ 239 CH₃ CH₂ NHCOPh m. p. 96° C. 240 CH₃ CH₂ NHCO(2-Cl-Ph) 241 CH₃ CH₂ NHCO(3-Cl-Ph) 242 CH₃ CH₂ NHCO(4-Cl-Ph) 243 CH₃ CH₂ NHCO(2-CH₃-Ph) 244 CH₃ CH₂ NHCO(3-CH₃-Ph) 245 CH₃ CH₂ NHCO(4-t-C₄H₉-Ph) 246 CH₃ CH₂ NHCO(3-CF₃-Ph) 247 CH₃ CH₂ NHCO(4-CF₃-Ph) 248 CH₃ CH₂ NHCO(2,4-(CH₃)₂-Ph) 249 CH₃ CH₂ NHCO(3,4-(CH₃)₂-Ph) 250 CH₃ CH₂ NHCO(4-OH-Ph) 251 CH₃ CH₂ NHCO(4-CH₃O-Ph) 252 CH₃ CH₂ NHCO(4-CF₃O-Ph) 253 CH₃ CH₂ NHCO(2,4-(CH₃O)₂-Ph) 254 CH₃ CH₂ NHCO(3,4-(CH₃O)₂-Ph) 255 CH₃ CH₂ NHCO(4-NH₂-Ph) 256 CH₃ CH₂ NHCO(4-NO₂-Ph) 257 CH₃ CH₂ NHCO(4-COOCH₃-Ph) 258 CH₃ CH₂ NHCO(2,4-C₁₂-Ph) 259 CH₃ CH₂ NHCO(3,4-Cl₂-Ph) 260 CH₃ CH₂ N(CHO)₂ m. p. 70-75° C. 261 CH₃ CH₂ Q₁₀ 262 CH₃ CH₂ 3,3,4,4,5,5-F₆—Q₁₁ 263 CH₃ CH₂ Q₁₂ m. p. 124-125° C. 264 CH₃ CH₂ NHCOOCH₃ 265 CH₃ CH₂ NHCOOC₂H₅ Paste 266 CH₃ CH₂ NHCOOC₄H₉-i 267 CH₃ CH₂ NHCOOC₄H₉-t 268 CH₃ CH₂ NHCOO(4-NO₂-Ph) 269 CH₃ CH₂ NHCOOPh 270 CH₃ CH₂ NHCONHCH₃ 271 CH₃ CH₂ NHCONHC₂H₅ 272 CH₃ CH₂ NHCONHC₃H₇-i 273 CH₃ CH₂ NHCONHPh m. p. 145° C. 274 CH₃ CH₂ NHCONH(2-Cl-Ph) 275 CH₃ CH₂ NHCONH(3-Cl-Ph) 276 CH₃ CH₂ NHCONH(4-Cl-Ph) 277 CH₃ CH₂ NHCONH(2-CH₃-Ph) 278 CH₃ CH₂ NHCONH(3-CH₃-Ph) 279 CH₃ CH₂ NHCONH(4-t-C₄Hg-Ph) 280 CH₃ CH₂ NHCONH(3-CF₃-Ph) 281 CH₃ CH₂ NHCONH(4-CF₃-Ph) 282 CH₃ CH₂ NHCONH(2,4-(CH₃)₂-Ph) 283 CH₃ CH₂ NHCONH(3,4-(CH₃)₂-Ph) 284 CH₃ CH₂ NHCONH(4-OH-Ph) 285 CH₃ CH₂ NHCONH(3-CH₃O-Ph) 286 CH₃ CH₂ NHCONH(4-i-C₃H₇O-Ph) 287 CH₃ CH₂ NHCONH(4-CF₃O-Ph) 288 CH₃ CH₂ NHCONH(2,4-(CH₃O)₂-Ph) 289 CH₃ CH₂ NHCONH(3,4-(CH₃O)2-Ph) 290 CH₃ CH₂ NHCONH(4-NH₂-Ph) 291 CH₃ CH₂ NHCONH(4-NO₂-Ph) 292 CH₃ CH₂ NHCONH(4-COOCH₃-Ph) 293 CH₃ CH₂ NHCONH(2,4-C₁₂-Ph) 294 CH₃ CH₂ NHCSNHCH₃ 295 CH₃ CH₂ NHCSNHPh m. p. 171-172° C. 296 CH₃ CH₂ NHC(═NCH₃)OC₂H₅ 297 CH₃ CH₂ NHC(═NPh)N(C₂H₅)₂ 298 CH₃ CH₂ NHC(═NPh)SCH₃ 299 CH₃ CH₂ NHSO₂(4-CH₃-Ph) Paste 300 CH₃ CH₂ NHNH₂ 301 CH₃ CH₂ NHN═C(CH₃)₂ 302 CH₃ CH₂ NHN═CHPh 303 CH₃ CH₂ NHN═C(CH₃)ph 304 CH₃ CH₂ Q₃ 305 CH₃ CH₂ Q₁₄ 306 CH₃ CH₂ Q₁₆ 307 CH₃ CH₂ CHO 308 CH₃ CH₂ CN 309 CH₃ CH₂ COOCH₃ 310 CH₃ CH₂ COOC₂H₅ 311 CH₃ CH₂ COOC₃H₇-i 312 CH₃ CH₂ COOC₈H₁₇-n 313 CH₃ CH₂ COOCH₂CH═CH₂ 314 CH₃ CH₂ CONH₂ 315 CH₃ CH₂ CONHCH₃ 316 CH₃ CH₂ CONHC₃H₇-i 317 CH₃ CH₂ CON(CH₃)₂ 318 CH₃ CH₂ CO—Q₁₆ 319 CH₃ CH₂ CO—Q₁₇ 320 CH₃ CH₂ CO—Q₁₈ 321 CH₃ CH₂ CO—Q₁₉ 322 CH₃ CH₂ CH(CCCH₃)₂ 323 CH₃ CH₂ CH(COOC₂H₅)₂ 324 CH₃ CH₂ C(NHCOCH₃)(COCC₂H₅)₂ m. p. 93-97° C. 325 CH₃ CH₂ CH(SCH₃)(SOCH₃) 326 CH₃ CH₂ Q₂₀ 327 CH₃ CHCl COOCH₃ nD 1. 5456(23° C.) 328 CH₃ CHCH₃ CN 329 CH₃ CHCH₃ COOCH₃ 330 CH₃ C(CH₃)₂ CN 331 CR₃ C(CH₃)₂ COOCH₃ 332 CH₃ CHPh Cl nD 1.5979(21.8° C.) 333 CH₃ CHPh OH m. p. 93.2° C. 334 CH₃ CHPh OCH₃ 335 CH₃ CHPh CN 336 CH₃ CHPh COOH 337 CH₃ CH₂CH₂ COOCH₃ 338 CH₃ CH═CH (E) COOCH₃ m. p. 70° C. 339 CH₃ CH═CH (E) CON(CH₃)₂ 340 CH₃ CH═CH (E) CONHPh 341 CH₃ CH═CH (Z) COOCH₃ m. p. 80-85° C. 342 CH₃ CH═CH CHO m. p. 77-78° C. (E, Z mixture) 343 CH₃ C═C(SCH₃)₂ CN 344 CH₃ Q₂₁ CN 345 CH₃ C═C(COOCH₃)₂ H 346 CH₃ C═C(COOCH₃)CN H Paste 347 CH₃ Q₂₂ CN 348 C₂H₅ CH₂ Cl 349 C₂H₅ CH₂ OH 350 C₂H₅ CH₂ OCH₃ 351 C₂H₅ CH₂ OCH₂Ph 352 C₂H₅ CH₂ OCH₂(4-C₂H₅—Q₁) 353 C₃H₇-i CH₂ F 354 C₃H₇-i CH₂ Cl 355 C₃H₇-i CH₂ Br 356 C₃H₇-i CH₂ I 357 C₃H₇-i CH₂ OH 358 C₃H₇-i CH₂ OCH₃ 359 C₃H₇-i CH₂ OCH₂Ph 360 C₃H₇-i CH₂ OCH₂(4-i-C₃H₇—Q₁) 361 C₃H₇-i CH₂ NH₂.HCl 362 C₃H₇-i CH₂ N(CH₃)₂ 363 C₃H₇-i CH₂ N(CH₂CH═CH₂)₂ 364 C₃H₇-i CH₂ NHCOCH₃ 365 CH₂Cl CH₂ OH Paste 366 CF₃ CH₂ OH 367 Ph — Q₄ m. p. 150° C. 368 Ph — Q₅ m. p. 158° C. 369 Ph — 5-(CH₃)₂—Q₅ m. p. 147° C. 370 Ph — 4-CH₃—Q₇ m. p. 161° C. 371 Ph — 4-t-C₄H₉—Q₇ m. p. 110° C. 372 Ph — 4-COOCH₃—Q₇ m. p. 124° C. 373 Ph — 4-CONHCH₃—Q₇ m. p. 187° C. 374 Ph — 4-CH₂COOH—Q₇ m. p. 137° C. 375 Ph — 4-CH₂CONH₂—Q₇ m. p. 137° C. 376 Ph — 4-CH₂CONHCH₃—Q₇ m. p. 154° C. 377 Ph — 5-CH₃—Q₂₃ m. p. 85° C. 378 Ph CH₂ Cl 379 Ph CH₂ OH 380 Ph CH₂ OCH₃ 381 Ph CH₂ OCH₂Ph 382 Ph CH₂ OCH₂(4-Ph—Q₁) 383 Ph CH₂ COOCH₃ 384 Ph CH₂ CON(CH₃)Ph 385 Ph CH₂ CONH(4-CH₃O-Ph) m. p. 129° C. 386 2-Cl-Ph CH₂ OH 387 3-Cl-Ph CH₂ OH 388 4-Cl-Ph CH₂ OH 389 4-CH₃-Ph CH₂ OH 390 3-CH₃-Ph CH₂ OH 391 4-CH₃-Ph CH₂ OH 392 4-t-C₄H₉-Ph CH₂ OH 393 2-CF₃-Ph CH₂ OH 394 4-CF₃-Ph CH₂ OH 395 2,4-(CH₃)₂-Ph CH₂ OH 396 3,4-(CH₃)₂-Ph CH₂ OH 397 4-OH-Ph CH₂ OH 398 4-CH₃O-Ph CH₂ OH 399 4-CF₃O-Ph CH₂ OH 400 4-PhO-Ph CH₂ OH 401 2,4-(CH₃O)₂-Ph CH₂ OH 402 3,4-(CH₃O)₂-Ph CH₂ OH 403 4-COOCH₃-Ph CH₂ OH 404 2,4-Cl₂-Ph CH₂ OH 405 3,4-Cl₂-Ph CH₂ OH 406 Q₂₄ CH₂ OH 407 Q₂₅ CH₂ OH 408 Q₂₆ CH₂ OH 409 Q₂₇ CH₂ OH m. p. 158° C. 410 Q₂₈ CH₂ OH 411 6-Cl—Q₂₇ CH₂ OH 412 Q₂₇ — CN m. p. 129° C. 413 4-F-Ph CH₂ O—CO-(4-Cl-Ph) m. p. 79° C. 414 4-F-Ph CH₂ O-(4-CH₃O-Ph) m. p. 86° C. 415 4-F-Ph CH₂ O—CO—CH₂-(4-CH₃-Ph) m. p. 113° C. 416 4-F-Ph CH₂ O—CO—NH-Ph m. p. 99° C. 417 4-F-Ph CH₂ ON═C(CH₃)(4-Cl-Ph) m. p. 91° C. 418 4-F-Ph CH₂ OH m. p. 100° C. 419 4-F-Ph CH₂ Br m. p. 88° C. 420 4-F-Ph CH₂ O—CO—CH₃ m. p. 59° C. 421 Q₂₆ — CN m. p. 190° C. 422 Ph CH₂ CONH-(4-CH₃O-Ph) m. p. 129° C. 423 Ph — C═NOH(NH₂) m. p. 130° C. 424 Ph — CN 425 CH₃ — Q₈ Paste 426 CH₃ — 5-CH₃—Q₈ nD 1.5661(26.4° C.) 427 CH₃ — SCH₂CH═CH₂ Paste 428 CH₃ — SCH₂C≡CH Paste 429 CH₃ — SCH₂-Ph m. p. 89° C. 430 CH₃ — SCH₂-(4-t-C₄H₉-Ph) m. p. 79° C. 431 CH₃ — S—C₃H₇-i Paste 432 CH₃ — S—CH₂—Q₂₇ m. p. 78° C. 433 CH₃ — S—CH₂—Q₂₃ m. p. 97° C.

In some of the compounds shown in Table 1, property is expressed by a term of “Paste”. Table 2 summarizes the data concerning these compounds.

TABLE 2 No H-NMR[CDCl₃/TMS, & value (ppm)] 208 2.46(s,3H), 2.63(s,3H), 5.35(s,2H), 7.35(d,2H), 7.77(d,2H). 221 1.05(t,6H), 2.54(q,4H), 2.63(s,3H), 3.78(s,2H). 222 2.61(s,3H), 3.10-3.12(m,4H), 3.80(s,2H), 5.16-5.24(m,4H), 5.78-5.89(m,2H). 265 1.25(t,3H), 2.63(s,3H), 4.15(q,2H), 4.59(d,2H), 5.2-5.35(br,1H). 299 2.44(s,3H), 2.58(s,3H), 4.42(d,2H), 5.37(br,t,1H), 7.31(d,2H), 7.70(d,2H). 346 1.41(t,3H), 2.90(s,3H), 4.20(q,2H), 8.34(s,1H). 365 2.58(t,1H), 5.03(s,2H), 5.16(d,2H). 426 3.08(s,3H), 3.96(d,2H), 5.27(d,1H), 5.43(d,1H), 6.00(m,1H). 427 3.08(s,3H), 5.23(d,2H), 6.28(s,1H). 430 1.55(d,6H), 3.08(s,3H), 4.02(m,1H).

The 1,2,3-thiadiazole derivatives of the general formula (I) or salts thereof according to the present invention are useful for agricultural and horticultural disease control. For example, these compounds have a very high controlling effect against various diseases, for instance, rice blast (Pyricularia oryzae), rice sheath blight (Rhizoctonia solani), rice helminthosporium leaf spot (Cochiobolus miyabeanus), powdery mildew of various host plants such as powdery mildew of barley and wheat (Erysiphe graminis), oats crown rust (Puccinia coronata) and rust of other plants, tomato late blight (Phytophthora infestans) and late blight or Phytophthora rots of other plants, downy mildew of various plants such as cucumber downy mildew (Pseudoperonospora cubensis) and grape downy mildew (Plasmopara viticola), apple scab (Venturia inaequalis), apple alternaria leaf spot (AlternariA mali), pear black spot (Alternaria kikuchiana), citrus melanose (Diaporthe citri), bacterial diseases including Pseudomonas diseases such as cucumber bacterial blight (Pseudomonas syrinaae pv. lachrymans) and tomato bacterial wilt (Pseudomonas solanacearum), Xanthomonas diseases such as cabbage black rot (Xanthomonas campestris), rice bacterial leaf blight (Xanthomonas oryzae) and citrus canker (Xanthomonas citri) and Erwinia diseases such as cabbage bacterial soft rot (Erwinia carotovora), and viral diseases such as tobacco mosaic (Tobacco mosaic virus).

The agrohorticultural disease controller containing the 1,2,3-thiadiazole derivative of general formula (I) or salts thereof as an active ingredient according to the present invention exhibits a marked controlling effect against the above-exemplified diseases which damage paddy field crops, upland field crops, fruit trees, vegetables, other crop plants, flowers, ornamental plants, and the like. Accordingly, the desired effects of the agrohorticultural disease controller of the present invention can be exhibited by applying the disease controller to the paddy field water, stalks and leaves or soil of the paddy field, upland field, fruit trees, vegetables, other crops, flowers and ornamental plants at a season at which the diseases are expected to occur, either before their occurrence or at the time when their occurrence has been confirmed.

The agrohorticultural disease controller of the present invention is generally put to use after being prepared into a conveniently usable form according to an ordinary manner for preparation of pesticides.

That is, the 1,2,3-thiadiazole derivative represented by the general formula (I) or a salt thereof according to the present invention and, optionally, an adjuvant are blended with an appropriate inert carrier in a proper proportion and dissolved, separated, suspended, mixed, impregnated, adsorbed or stuck, prepared into a suitable preparation form such as suspension, emulsifiable concentrate, soluble concentrate, wettable powder, granule, dust, tablet, etc. and put to use.

The inert carrier used in the present invention may be either solid or liquid. As the material usable as solid carrier, there can be exemplified soybean flour, cereal flour, wood flour, bark flour, saw dust, powdered tobacco stalks, powdered walnut shells, bran, powdered cellulose, extraction residue of vegetables, powdered synthetic polymers of synthetic resins and the like, clays such as kaolin, bentonite, acid clay and the like, talcs such as talc, pyrophyllite and the like, silica materials such as diatomaceous earth, siliceous sand, mica, white carbon (namely, synthetic, high-dispersion silicic acid , also called finely divided hydrated silica or hydrated silicic acid, some of the commercially available products thereof contain calcium silicate as the major component), activated carbon, powdered sulfur, pumice, calcined diatomaceous earth, crushed brick, fly ash, sand, inorganic mineral powders such as calcium carbonate, calcium phosphate and the like, chemical fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, urea, ammonium chloride and the like, and compost. These carriers may be used alone or as a mixture thereof.

The material constituting the liquid carrier is selected from materials having a dissolving ability in themselves and materials which have no dissolving ability in themselves but can disperse the active ingredient compound by the aid of an adjuvant. The following are typical examples of the liquid carrier material, which can be used either alone or in the form of a mixture: water; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol and the like; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone and the like; ethers such as ethyl ether, dioxane, cellosolve, dipropyl ether, tetrahydrofuran and the like; aliphatic hydrocarbons such as kerosene, mineral oils and the like; aromatic hydrocarbons such as benzene, toluene, xylene, solvent naphtha, alkyl-naphthalene and the like; halogenated hydrocarbons such as dichloroethene, chloroform, carbon tetrachloride, chlorobenzene and the like; esters such as ethyl acetate, diisopropyl phthalate, dibutyl phthalate, dioctyl phthalate and the like; amides such as dimethylformamide, diethylformamide, dimethylacetamide and the like; nitriles such as acetonitrile and the like; dimethyl sulfoxide; etc.

As the adjuvant, the following can be referred to as typical ones. These adjuvants are used depending upon purposes, either alone or in combination of two or more in some cases. It is also possible to use no adjuvant at all, in some cases.

A surfactant is used for the purpose of emulsifying, dispersing, solubilizing and/or wetting an active ingredient compound. As the surfactant, there can be exemplified polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene higher fatty acid esters, polyoxyethylene resin acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, alkylarylsulfonates, naphthalene-sulfonic acid condensates, ligninsulfonic acid salts, higher alcohol sulfuric esters, etc.

The following adjuvants can also be used for the purpose of stabilizing, tackifying and/or binding the dispersion of active ingredient compound: casein, gelatin, starch, methyl cellulose, carboxymethyl cellulose, gum arabic, polyvinyl alcohol, turpentine, bran oil, bentonite, ligninsulfonic acid salts and the like.

Further, wax, stearic acid salts, alkyl phosphates and the like may be used as an adjuvant for the purpose of improving flowability of a solid product.

Further, naphthalenesulfonic acid condensates, polycondensed phosphoric acid salts and the like may also be used as a peptizer for dispersible products.

Adjuvants such as silicone oils may also be used as a defoaming agent.

The content of the active ingredient compound may be increased or decreased according to the need. For example, in dusts and granules, the suitable content thereof is from 0.01 to 50% by weight. In emulsifiable concentrates and wettable powders, too, the suitable content thereof is from 0.01 to 50% by weight.

For controlling various diseases, the agrohorticultural disease controller of the present invention itself or its appropriate dilution or suspension in water or the like is applied to a crop on which the diseases are expected to occur or a site where occurrence of the diseases is undesirable, in an amount effective for disease control. For example, for controlling the diseases of paddy rice, said disease controller can be used by a method such as direct application to regular paddy field, application to a rice nursery bed, dressing of seeds for direct sowing to flooded paddy field, seed disinfection, etc. For controlling the diseases of barley, wheat, oat or the like, the disease controller of the present invention is applied to stalks and leaves or used for soil treatment where the disease controller is absorbed from the roots.

The application amount of the agrohorticultural disease controller of the present invention may vary depending on various factors including purpose of application, objective disease, state of plant growth, tendency of prevalence of the disease, weather, environmental conditions, preparation form, method of application, site of application, time of application, etc. The application amount, however, should be properly chosen in the range of from 0.1 g to 10 kg per 10 ares as expressed in terms of amount of active ingredient compound, depending on purposes.

In order to expand the spectrum of controllable diseases and the time period of effective application or to reduce the dosage, it is also possible to use the disease controller of the present invention in the form of a mixture with other agrohorticultural disease controllers.

Next, typical examples, formulation examples and test examples of the 1,2,3-thiadiazole derivatives of general formula (I) or salts thereof according to the present invention are presented below. The present invention is by no means limited by these examples.

EXAMPLE 1 Production of 4-methyl-1,2,3-thiadiazole-5-carbaldehyde (Compound No. 7)

In 25 ml of methylene chloride were suspended 9.9 g (46 mmol) of pyridinium chlorochromate and 10 g of silica gel. After adding 3.0 g (23 mmol) of 4-methyl-1,2,3-thiadiazol-5-ylmethanol, the mixture was stirred at room temperature for 4 hours to make a reaction progress. After the reaction was completed, the reaction mixture was diluted with ether, the resulting florisil was filtered off, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography using 3:1 mixture of n-hexane and ethyl acetate. Thus, 2.0 g of the objective compound was obtained.

Property: nD 1.5555 (26° C.)

Yield: 62%

EXAMPLE 2 Production of 5-benzoyl-4-methyl-1,2,3-thiadiazole (Compound No. 9)

To 2.0 g (15 mimol) of thionyl chloride was added 0.50 g (3.5 mmol) of 4-methyl-1,2,3-thiadiazole-5-carboxylic acid. After heating the mixture with stirring for 2 hours, the thionyl chloride was distilled off under reduced pressure, and the residue was added to a solution of 1.8 g (15 mmol) of aluminum chloride in 20 ml benzene and made to react with heating for 3 hours. After the reaction was completed, the reaction mixture was poured into ice water, the objective product was extracted with ethyl acetate, the organic layer was ashed with a saturated aqueous solution of sodium chloride and dried, the solvent was distilled off under educed pressure, and the residue was purified by silica gel column chromatography using 4:1 mixture of n-hexane and ethyl acetate. Thus, 0.69 g of the objective compound was obtained.

Property: nD 1.6145 (22° C.)

Yield: 97%

EXAMPLE 3 Production of O-benzyl-4-methyl-1,2,3-thiadiazole-5-carbaldehyde oxime (Compound No. 21)

To 10 ml of ethanol were added 0.40 g (3.1 mmol) of 4-methyl-1,2,3-thiadiazole-5-carbaldehyde obtained in Example 1, 0.60 g (3.8 mmol) of benzyloxyamine hydrochloride and 0.50 g (3.8 mmol) of sodium acetate. The mixture was stirred for 4 hours with heating under reflux. After the reaction was completed, the reaction mixture was diluted with ethyl acetate and filtered to remove the precipitate, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography using 4:1 mixture of n-hexane and ethyl acetate. Thus, 0.66 g of the objective compound was obtained.

Property: nD 1.5998 (25° C.)

Yield: 91%

EXAMPLE 4 Production of 5-(5-mercapto-1,3,4-oxadiazol-2-yl)-4-methyl-1,2,3-thiadiazole (Compound No. 102)

A solution of 0.3 g of potassium hydroxide in 1 ml water and 0.6 ml of carbon disulfide were successively added to a solution of 1.1 g (7.2 mmol) of 4-methyl-1,2,3-thiadiazole-5-carbohydrazide in 15 ml ethanol. The mixture was stirred for 6.5 hours with heating under reflux. After the reaction was completed, the solvent was distilled off under reduced pressure, water was added to the residue, acetic acid was added for the sake of acidification, and the deposited crystalline product was collected by filtration. Thus, 0.82 g of the objective compound was obtained.

Property: m.p. 182° C.

Yield: 59%

EXAMPLE 5 Production of 4-methyl-5-(5-methylthio-1,3,4-oxadiazol-2-yl)-1,2,3-thiadiazole (Compound No. 103)

To 10 ml of acetone were added 0.40 g (2.0 mmol) of 5-(5-mercapto-1,3,4-thiadiazol-2-yl)-4-methyl-1,2,3-thiadiazole, 0.43 g (3.0 mmol) of methyl iodide and 0.83 g (6.0 mmol) of potassium carbonate. The mixture was stirred for 5 hours with heating under reflux. After the reaction was completed, the reaction mixture was filtered to remove the insoluble matter, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography using 2:1 mixture of n-hexane and ethyl acetate. Thus, 0.41 g of the objective compound was obtained.

Property: m. p. 65° C.

Yield 96%

EXAMPLE 6 Production of 5-chloromethyl-4-methyl-1,2,3-thiadiazole (Compound No. 104)

While cooling the reaction system with ice, 2 ml of thionyl chloride was added to 0.50 g (3.8 mmol) of 4-methyl-1,2,3-thiadiazol-5-ylmethanol. Then, at room temperature, the mixture was stirred for 2 hours. Then, water was added to stop the reaction, the objective product was extracted with ethyl acetate, the organic layer was washed with water and dried, the solvent was distilled off under reduced pressure, and the residue thus obtained was purified by silica gel column chromatography using 3:1 mixture of n-hexane and ethyl acetate. Thus, 0.46 g of the objective compound was obtained.

Property: nD 1.5590 (26° C.)

Yield: 81%

EXAMPLE 7 Production of 4-methyl-1,2,3-thiadiazol-5-ylmethanol (Compound No. 105)

To a solution of 0.10 g (2.5 mmol) of sodium hydroxide in 10 ml ethanol was added 1.0 g (5.8 mmol) of ethyl 4-methyl-1,2,3-thiadiazole-5-carboxylate. Then, 0.33 g (8.7 mmol) of sodium borohydride was added and stirred at room temperature. After the reaction was completed, water was added to the reaction mixture to decompose the excessive sodium borohydride, after which the objective product was extracted with ethyl acetate. The organic layer was washed with water and dried, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 2:1 mixture of n-hexane and ethyl acetate. Thus, 0.36 g of the objective compound was obtained.

Property: nD 1.553 (21° C.)

Yield: 48%

EXAMPLE 8 Production of 4-methyl-5-benzyloxymethyl-1,2,3-thiadiazole (Compound No. 109)

In 10 ml of acetone was dissolved 0.40 g (3.1 mmol) of 4-methyl-1,2,3-thiadiazol-5-ylmethanol. After adding 1.6 g (12 mmol) of potassium carbonate and 0.80 g (4.5 mmol) of benzyl bromide, the resulting mixture was stirred for 10 hours with heating under reflux. After the reaction was completed, the insoluble matter was filtered off, the solvent was distilled off from the filtrate under reduced pressure, and the residue was purified by silica gel column chromatography using 3:1 mixture of n-hexane and ethyl acetate. Thus, 0.65 g of the objective compound was obtained.

Property: nD 1.5730 (25° C.)

Yield 96%

EXAMPLE 9 Production of 4,4′-dimethyl-5,5′-oxybis(methyl-1,2,3-thiadiazole) (Compound No. 129)

In 20 ml of tetrahydrofuran were dissolved 2.0 g (15 mmol) of 4-methyl-1,2,3-thiadiazol-5-ylmethanol and 3.9 g (39 mmol) of triethylamine. While cooling the system with ice, 3.5 g (18 mmol) of tosyl chloride was added and stirred at room temperature for 24 hours. Then, a saturated aqueous solution of sodium chloride was added to the reaction mixture to stop the reaction, the objective product was extracted with ethyl acetate, the extract solution was washed successively with dilute hydrochloric acid, a saturated aqueous solution of sodium hydrogen carbonate and a saturated aqueous solution of sodium chloride, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 4:1 mixture of n-hexane and ethyl acetate. Thus, 1.1 g of the objective compound was obtained.

Property: nD 1.547 (26° C.)

Yield: 57%

EXAMPLE 10 Production of 4-methyl-1,2,3-thiadiazol-5-ylmethyl acetate (Compound No.150)

In 10 ml of tetrahydrofuran were dissolved 0.50 g (3.8 mmol) of 4-methyl-1,2,3-thiadiazol-5--ylmethanol, 0.50 g (5.7 numol) of acetyl chloride and 0.80 g (7.6 mmol) of triethylamine. The solution thus obtained was stirred at room temperature for 18 hours. Then, a saturated aqueous solution of sodium chloride was added to the reaction mixture to stop the reaction, the objective product was extracted with ethyl acetate, the organic layer was washed with water and dried, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 3:1 mixture of n-hexane and ethyl acetate. Thus, 0.70 g of the objective compound was obtained.

Property: nD 1.3580 (25° C.)

Yield: 100%

EXAMPLE 11 Production of ethyl 4-methyl-1,2,3-thiadiazol-5-ylmethyl carbonate (Compound No. 180)

In 5 ml of tetrahydrofuran was dissolved 0.50 g (3.8 mmol) of 4-methyl-1,2,3-thiadiazol-5-ylmethanol. After adding 0.80 g (7.6 mmol) of triethylamine and 0.60 g (5.7 mmol) of ethyl chlorocarbonate, the resulting mixture was stirred at room temperature for 22 hours. Then, water was added to the reaction mixture to stop the reaction, the objective product was extracted with ethyl acetate, the organic layer was washed with water and dried, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 5:1 mixture of n-hexane and ethyl acetate. Thus, 0.50 g of the objective compound was obtained.

Property: nD 1.5041 (26° C.)

Yield: 68%

EXAMPLE 12 Production of 4-methyl-5-phenylthiomethyl-1,2,3-thiadiazole (Compound No. 209)

At an ice-cooled temperature, 3 ml of thionyl chloride was added to 0.50 g (3.8 mmol) of 4-methyl-1,2,3-thiadiazol-5-ylmethanol and stirred for 4 hours. Then, the reaction mixture was concentrated under reduced pressure, and 1.30 g (11.5 mmol) of potassium carbonate, 0.38 g (3.4 mmol) of thiophenol and 10 ml of acetone were added to the concentrate and reacted for 7 hours with heating under reflux. After the reaction was completed, the reaction mixture was cooled to room temperature, the precipitated matter was filtered off, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 5:1 mixture of n-hexane and ethyl acetate. Thus, 0.64 g of the objective compound was obtained.

Property: nD 1.636 (25° C.)

Yield: 85%

EXAMPLE 13 Production of 4-methyl-5-phenylsulfonylmethyl-1,2,3-thiadiazole (Compound No. 211)

In 5.0 ml of methylene chloride was dissolved 0.20 g (0.99 mmol) of 4-methyl-5-phenylthiomethyl-1,2,3-thiadiazole. Then, 0.40 g (2.3 mmol) of m-chloroperbenzoic acid was added to the solution obtained above, and was stirred for 20 hours at room temperature. Then, an aqueous solution of sodium hydrogen sulfite was added to the reaction mixture to stop the reaction, the objective product was extracted with ethyl acetate, the organic layer was washed with a saturated aqueous solution of sodium hydrogen carbonate, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 2:1 mixture of n-hexane and ethyl acetate. Thus, 0.23 g of the objective compound was obtained.

Property: m.p. 118° C.

Yield: 100%

EXAMPLE 14 Production of 5-aminomethyl-4-methyl-1,2,3-thiadiazole hydrochloride (Compound No. 220)

To 50 ml of acetonitrile were added 7.0 g (47 mmol) of 5-chloromethyl-4-methyl-1,2,3-thiadiazole and 9.0 g (94 mmol) of sodium formimide. After stirring the resulting mixture for 16 hours with heating under reflux, the reaction mixture was cooled to the room temperature, a saturated aqueous solution of sodium chloride was added, the objective product was extracted with ethyl acetate, the organic layer was washed with water and dried, and the solvent was distilled off under reduced pressure. Then, while stirring the resulting crystalline product together with 40 ml of water, 30 ml of concentrated hydrochloric acid was added. After ten minutes, water and hydrochloric acid were distilled off, and the residue was washed with ethyl acetate. Thus, 6.6 g of the objective compound was obtained.

Property: m.p. >250° C.

Yield: 77%

EXAMPLE 15 Production of 5-(N,N-diallylamino)methyl-4-methyl-1,2,3-thiadiazole (Compound No. 222)

To 15 ml of acetone were added 0.50 g (3.0 mmol) of 5-aminomethyl-4-methyl-1,2,3-thiadiazole hydrochloride, 1.10 g (9.0 mmol) of allyl bromide and 2.1 g (15 mmol) of potassium carbonate. The resulting mixture was stirred for 20 hours with heating under reflux. After the reaction was completed, the reaction mixture was filtered to remove the precipitated matter, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 3:1 mixture of n-hexane and ethyl acetate. Thus, 0.42 g of the objective compound was obtained.

Property: Pasty product

Yield: 67%

H-NMR [CDCl₃/TMS, β value (ppm)] 2.61 (s, 3 H), 3.10-3.12 (m, 4 H), 3.80 (s, 2 H), 5.16-5.24 (m, 4 H), 5.78-5.89 (m, 2 H)

EXAMPLE 16 Production of methyl (E)-3-(4-methyl-1,2,3-thiadiazol-5-yl)-2-propenate (Compound No. 338) and methyl (Z)-3-(4-methyl-1,2,3-thiadiazol-5-yl)-2-propenate (Compound No. 341)

To 0.40 g (3.1 mmol) of 4-methyl-1,2,3-thiadiazol-5-carbaldehyde dissolved in tetrahydrofuran was added 1.1 g (3.4 mmol) of methyltriphenylphos phoranylidensacetate. The solution thus obtained was stirred for 16 hours at room temperature. After the reaction was completed, the reaction mixture was cooled to room temperature, a saturated aqueous solution of sodium chloride was added, and the objective product was extracted with ethyl acetate. The organic layer was washed with water and dried, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 5:1 mixture of n-hexane and ethyl acetate. Thus, the E-compound and the Z-compound, both the objective compounds, were obtained in yields of 0.49 g and 0.05 g, respectively.

Property: E-compound m.p. 70° C., Yield 90%

Z-compound m.p. 80-85° C., Yield 10%

EXAMPLE 17 Production of ethyl 2-cyano-3-(4-methyl-1,2,3-thiadiazol-5-yl)-2-propenate (Compound No. 346)

To 50 ml of toluene were added 1.5 g (12 mmol) of 4-methyl-1,2,3-thiadiazole-5-carbaldehyde, 1.5 g (13 mmol) of ethyl cyanoacetate, 0.40 g (6.0 mmol) of pyrrolidine and 0.20 g (1.2 mmol) of tosylic acid. In a reactor equipped with a Dean-Stark dehydrating apparatus, the mixture obtained above was stirred for 2 hours with heating under reflux. After the reaction was completed, a saturated aqueous solution of sodium Achloride was added to the reaction mixture, the objective product was extracted with ethyl acetate, the organic layer was washed successively with dilute hydrochloric acid, saturated aqueous solution of sodium hydrogen carbonate and saturated aqueous solution of sodium chloride, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography using 3:1 mixture of n-hexane and ethyl acetate. Thus, 0.73 g of the objective compound was obtained.

Property: Pasty product,

Yield: 30%

H-NMR [CDCl₃/TMS, β value (ppm)] 1.41 (t, 3 H), 2.90 (s, 3 H), 4.20 (q, 2 H), 8.34 (s, 1 H)

EXAMPLE 18 Production of 4-phenyl-3,4,5,6-tetrahydro-pyrimidin-2-yl-1,2,3-thiadiazole (Compound No. 368)

In 10 ml of ethanol were dissolved 0.95 g (5.0 immol) of 4-phenyl-1,2,3-thiadiazole-5-carbonitrile and 3.8 g (50 mmol) of 1,3-propanediamine. After adding 0.05 g of sodium ethoxide, the solution thus obtained was stirred for 8 hours with heating under reflux. After the reaction was completed, the reaction mixture was cooled to room temperature, the solvent was distilled off under reduced pressure, and the objective product was extracted with ethyl acetate. The organic layer was concentrated under reduced pressure, and the oily product thus obtained was recrystallized from a small quantity of ethyl acetate to obtain 0.68 g of the objective compound.

Property: m.p. 158° C.

Yield: 55%

EXAMPLE 19 Production of methyl 2-(4-phenyl-1,2,3-thiadiazol-5-yl)thiazole-4-carboxylate (Compound No. 372)

In 20 ml of chlorobenzene were dissolved 1.1 g (5.0 mmol) of 4-phenyl-1,2,3-thiadiazole-5-carbothioamide and 0.92 g (5.0 mmol) of methyl bromopyruvate. The solution thus obtained was stirred for 3 hours with heating under reflux. After the reaction was completed, the reaction mixture was cooled to room temperature, a saturated aqueous solution of sodium hydrogen carbonate was added thereto, and the objective product was extracted with ethyl acetate. The solvent was distilled off from the extract solution under a reduced pressure, and the residue was purified by silica gel column chromatography using 3:1 mixture of n-hexane and ethyl acetate. Thus, 0.74 g of the objective compound was obtained.

Property: m.p. 124° C.

Yield: 41%

Next, typical formulation examples and test examples of the present invention are mentioned below.

In the formulation examples, the term “parts” means “parts by weight”.

Formulation Example 1

The compound shown in Table 1 50 parts Xylene 40 parts Mixture of polyoxyethylene nonyl- phenyl ether and calcium alkyl- benzenesulfonate 10 parts

The ingredients mentioned above are uniformly mixed and dissolved together to prepare an emulsifiable concentrate.

Formulation Example 2

The compound shown in Table 1 3 parts Clay powder 82 parts Diatomaceous earth powder 15 parts

The ingredients mentioned above are uniformly mixed together and pulverized to prepare a dust.

Formulation Example 3

The compound shown in Table 1 5 parts Powdery mixture of bentonite and 90 parts clay Calcium ligninsulfonate 5 parts

The ingredient mentioned above are kneaded together with a proper quantity of water, and then granulated and dried to prepare a granular composition.

Formulation Example 4

The compound shown in Table 1 20 parts Kaolinite and synthetic high- 75 parts dispersion silicic acid Mixture of polyoxyethylene 5 parts nonylphenyl ether and calcium alkylbenzenesulfonate

The ingredients mentioned above are uniformly mixed together and pulverized to prepare a wettable powder.

Test Example 1: Rice blast-controlling test by submerged application

A chemical agent containing the compound shown in Table 1 as an active ingredient was applied to paddy rice plants of the 5- to 6-leaved stage, cultivated in 1/10000 are pots, by the method of submerged application at a dosage of 200 g/10 ares as expressed in terms of active ingredient. After standing in a greenhouse for a week, the plants were inoculated with a spore suspension of rice blast fungus (Pyricularia oryzae) by the method of spraying.

After the inoculation, the plants were allowed to stand in a moist chamber for one day and then in a greenhouse for 6 days to cause the disease sufficiently. Then, lesions on each leaf were counted and compared with those in the untreated plot, from which the controlling degree was calculated, whereby the effect was judged according to the following criterion:

Effect Controlling degree (%) A 100-95  B 94-85 C 84-60 D 59-0 

The results of the above test demonstrate that the compounds listed in Table 1 were found to have a marked blast-controlling activity. Of these compounds, the following were rated C or higher: Compound Nos. 7, 17-19, 21, 24, 35, 36, 60, 62, 66-69, 77, 83, 84, 87-89, 91, 93-100, 102, 104-106, 109, 129, 150, 162, 180, 209, 220-222, 229, 239, 260, 263, 273, 295, 299, 327, 338, 341, 342, 346, 365, 367, 369, 371 and 376. Especially, the following exhibited so excellent a blast-controlling activity as rated A: Compound Nos. 7, 37, 88, 89, 91, 104, 105, 109, 129, 150, 220, 221, 222, 239, 260, 263, 273, 299, 327, 342, 367 and 371. 

What is claimed is:
 1. An agrohorticultural disease controller comprising as the active ingredient a 1,2,3-thiadiazole derivative represented by the following general formula (I) or a salt thereof:

wherein R¹ represents hydrogen atom, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, 5- or 6heterocycle containing 1 to 3 same or different heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups; A represents a group of the following formula:

(wherein R² and R^(3,) same or different, represent hydrogen atom, halogen atom, cyano group, formyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, C₁-C₄ alkylsulfinyl group, C₁-C₄ alkylsulfonyl group, C₁-C₄ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, C₁-C₄ alkyl group and C₁-C₄ alkoxycarbonyl group; further, R² and R³ may be taken conjointly to form a 3- to 7-membered ring including a C₂-C₆ alkylene group which may be intercepted by —O—, —S (O)_(n)—in which n is an integer of 0 to 2, —CO— or —NR⁸— in which R⁸ represents hydrogen atom, formyl group, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, C₂-C₄ alkenyl group, halo C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, halo C₂-C₄ alkynyl group, C₁-C₄ alkylthio group, C₁-C₄ alkylsulfinyl group, C₁-C₄ alkylsulfonyl group, C₁-C₄ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group and phenyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group; and said 3- to 7-membered ring may be substituted by one or more same or different substituents selected from the group consisting of halogen atom and C₁-C₄ alkyl group; and m represents an integer of 0 to 4), or

in which R² and R³ are as defined above,

in which R² and R³ are as defined above,

in which R² and R³ are as defined above; and in the case that m is 0 in the definition of A, B represents, 5- or 6-membered heterocycle having 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different C₁-C₄ alkyl or phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 C₁-C₄ alkyl or phenyl groups, carbamoyl C₁-C₄ alkyl group and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different C₁-C₄ alkyl or phenyl groups, or —C(═X)R⁴ (in which R⁴ represents hydrogen atom, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, C₂-C₄ alkenyl group, halo C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, halo C₂-C₄ alkynyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6 membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group and phenyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group and phenyl group, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group and phenyl group, and X represents O, S, N—R⁶ in which R⁶ is as defined later, NO—R⁶ in which R⁶ is as defined later, N(≦O)—R⁶ in which R⁶ is as defined later, NN(R⁶)R⁷ in which R⁶ and R⁷ are as defined later, or NN═C(R⁶)R⁷ (in which R⁶ and R⁷, same or different, represent hydrogen atom, halogen atom, formyl group, C₁-C₄ alkyl group, C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, C₁-C₄ alkylsulfonyl group, halo C₁-C₄ alkylsulfonyl group, C₁-C₂₀ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group, amino group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group, amino group and C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, substituted phenylcarbonyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group, phenyl group and substituted phenyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group and halo C₁-C₄ alkoxy group, phenylsulfonyl group, substituted phenylsulfonyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, thiocarbamoyl group, substituted thiocarbamoyl group substituted by same or different C₁-C₄ alkyl or phenyl group, C₁-C₄ alkoxy carbonimidoyl group, substituted C₁-C₄ alkoxy carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylthio carbonimidoyl group, substituted C₁-C₄ alkylthio carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylsulfinyl carbonimidoyl group, substituted C₁-C₄ alkylsulfinyl carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylsulfonyl carbonimidoyl group, substituted C₁-C₄ alkylsulfonyl carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, amidino group, substituted amidino group having same or different substituents selected from the group consisting of C₁-C₆ alkyl and phenyl groups, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups; and R⁶ and R⁷ may be taken conjointly to form a 3- to 7-membered ring including a C₂-C₆ alkylene group which may be intercepted by —O—, —S(O)_(n)— in which n is as defined above, —CO—, or —NR⁸— in which R⁸ is as defined above, and said 3- to 7-membered ring may have same or different substituents selected from the group consisting of halogen atom and C₁-C₄ alkyl group)); and in cases where m is 1 or greater, B represents hydrogen atom, halogen atom, cyano group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 3 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, —C(═X) R⁵ (in which X is as defined above; and R⁵ represents hydrogen atom, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, C₂-C₄ alkenyl group, halo C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, halo C₂-C₄ alkynyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, 5- to 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, O—R⁶ in which R is as defined above, S(O)_(n)—R⁶ in which n and R⁶ are as defined above, or N(R⁶)R⁷ in which R⁶ and R⁷ are as defined above),

(wherein R⁵ is as defined above; and R⁹ and R¹⁰, same or different, represent formyl group, C₁-C₄ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group; firther, R⁹ and R¹⁰ may be taken conjointly to form a 3- to 7-membered ring including a C₂ to C₆ alkylene group which may be intercepted by —O—, —S(O)_(n)— in which n is as defined above, —CO—, or —N(R⁸)— in which R⁸ is as defined above, and said 3- to 7-membered ring may have one or more same or different substituents selected from the group consisting of halogen atom and C₁-C₄ alkyl group), O—R⁶ in which R⁶ is as defined above, S(O)_(n)—R₆ in which R₆ and n are as defined above, N(R⁶)R⁷ in which R⁶ and R⁷ are as defined above, N═C(R⁶)R⁷ in which R⁶and R⁷ are as defined above, or ON═C(R⁶)R⁷ in which R⁶ and R⁷ are as defined above.
 2. An agrohorticultural disease controller comprising as the active ingredient a 1,2,3-thiadiazole derivative or a salt thereof, wherein R¹ represents hydrogen atom, C₁-C₈ alkyl group or halo C₁-C₄ alkyl group; A represents the following formula:

(wherein R² and R³, same or different, represent hydrogen atom, halogen atom, cyano group, formyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, C₁-C₄ alkylsulfinyl group, C₁-C₄ alkylsulfonyl group, C₁-C₄ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, Cl-C₄ alkoxy group, halo C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, C₁-C₄ alkyl group and C₁-C₄ alkoxycarbonyl group; and m represents an integer of 0 to 4) and in the case that m is 0 in the definition of A, B represents, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthio group, formyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, or —C(═X)R⁴ (in which R⁴ represents hydrogen atom, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ aLkoxycarbonyl group, or 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfuir atom; and X represents O, S, NO—R⁶ in which R⁶ is as defined later, or NN(R⁶)(R⁷)(in which R⁶ and R⁷, same or different, represent hydrogen atom, halogen atom, formyl group, C₁-C₄ alkyl group, C₂-C₄ alkenyl group, C₂-C₄ alkynyl group, C₁-C₄ alkylsulfonyl group, halo C₁-C₄ alkylsulfonyl group, C₁-C₂₀ alkylcarbonyl group, C₁-C₄ alkoxycarbonyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group, amino group and C₁-C₄ alkoxycarbonyl group, phenyl C₁-C₄ alkyl group, substituted phenyl C₁-C₄ alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group, amino group and C₁-C₄ alkoxycarbonyl group, phenylcarbonyl group, substituted phenylcarbonyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group, halo C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl group, phenyl group and substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, C₁-C₄ alkyl group, halo C₁-C₄ alkyl group, C₁-C₄ alkoxy group and halo C₁-C₄ alkoxy group, phenylsulfonyl group, substituted phenylsulfonyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, thiocarbamoyl group, substituted thiocarbamoyl group substituted by same or different C₁-C₄ alkyl or phenyl group, C₁-C₄ alkoxy carbonimidoyl group, substituted C₁-C₄ alkoxy carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylthio carbonimidoyl group, substituted C₁-C₄ alkylthio carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylsulfinyl carbonimidoyl group, substituted C₁-C₄ alkylsulfinyl carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, C₁-C₄ alkylsulfonyl carbonimidoyl group, substituted C₁-C₄ alkylsulfonyl carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, amidino group, substituted amidino group having same or different substituents selected from the group consisting of C₁-C₆ alkyl and phenyl groups, or 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom)); and in cases where m is 1 or greater, B represents hydrogen atom, halogen atom, cyano group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfuir atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 3 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, mercapto group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group, C₁-C₄ alkylthlio group, carbonyl group, carboxyl group, carboxy C₁-C₄ alkyl group, C₁-C₄ alkoxycarbonyl group, C₁-C₄ alkoxycarbonyl C₁-C₄ alkyl group, amino group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, carbamoyl C₁-C₄ alkyl group, and substituted carbamoyl C₁-C₄ alkyl group having 1 or 2 same or different substituents selected from the group consisting of C₁-C₄ alkyl and phenyl groups, —C(═X) R⁵ (in which X is as defined above; and R⁵ represents hydrogen atom, C₁-C₈ alkyl group, halo C₁-C₄ alkyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C₁-C₄ alkyl group, C₁-C₄ alkoxy group and C₁-C₄ alkoxycarbonyl group, 5- or 6-membered heterocycle having 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, O—R⁶ in which R⁶ is as defined above, S(O)_(n)—R⁶in which n and R⁶ are as defined above, or N(R⁶)R⁷ in which R⁶ and R⁷ are as defined above), O—R⁶ in which R⁶ is as defined above, S(O)_(n)—R⁶ in which n and R⁶ are as defined above, N(R⁶)R⁷ in which R⁶ and R⁷ are as defined above, N═C(R⁶)R⁷ in which R⁶ and R⁷ are as defined above, or ON═C(R⁶)R⁷ in which R⁶ and R⁷ are as defined above.
 3. A method for controlling a plant disease which comprises treating a plant on which occurrence of plant disease is undesirable with an effective quantity of the agrohorticultural disease controller according to claim
 1. 4. A method for controlling a plant disease which comprises treating a plant on which occurrence of plant disease is undesirable with an effective quantity of the agrohorticultural disease controller according to claim
 2. 